1. Field of the Invention
The present invention relates to a stereoscopic endoscope by which a part to be inspected such as the inside of a body cavity is stereoscopically observed by means of a pair of objective optical systems disposed at the front end of its inserting portion; and, more specifically, to a structure of the front end part of the inserting portion thereof.
2. Description of the Prior Art
Recently, surgical techniques in which endoscopes are used for observing parts to be inspected within body cavities and performing operations on diseased parts within the body cavities have been prevailing. For making diagnoses more accurately and alleviating the suffering of patients, the endoscopes have been technically improved. In particular, for performing a diagnosis more accurately within a body cavity, it is useful to obtain depth information within the body cavity. Stereoscopic endoscopes have been known to respond to such a demand.
It is important for a stereoscopic endoscope to easily combine its right and left images together and obtain an image which can readily yield a three-dimensional feel. For this purpose, while a pair of objective optical systems corresponding to the right and left eyes are assembled in the endoscope with their optical axes being parallel to each other or forming an angle of convergence therebetween, a high accuracy is required for the alignment of the objective optical systems for both eyes and other components in both cases.
However, highly accurate positioning of each optical system is hard to attain and is likely to yield numerous errors in assembly and adjustment. Also, it is problematic in that its working process becomes complicated.
For reducing such errors and simplifying the working process, it is desirable that its assembling step be configured as a unit. In the case of the front end part of the stereoscopic endoscope, its working process will be simplified if a lens barrel main body holding and accommodating the objective optical systems and a front end part main body attached to the object side thereof can be manufactured separately and assembled together easily.